Maria Montessori
Author of the method
Maria Montessori, born in 1870, was the first woman in Italy to receive a medical degree. She worked in the fields of psychiatry, education and anthropology. She believed that each child is born with a unique potential to be revealed, rather than as a "blank slate" waiting to be written upon. Her main contributions to the work of those of us raising and educating children are in these areas:

• Preparing the most natural and life-supporting environments for the child
• Observing the child living freely in this environment
• Continually adapting the environment so that the child may fulfill his or her greatest potential; physically, mentally, emotionally, and spiritually.
The teacher, when she begins to work in our schools, must have a kind of faith that the child will reveal himself through work.
She must free herself from all preconceived ideas concerning the levels at which the children may be. The many different types of children... must not worry her... The teacher must believe that this child before her will show his true nature when he finds a piece of work that attracts him. So what must she look out for? That one child or another will begin to concentrate. The teacher becomes the keeper and custodian of the environment. She attends to this instead of being distracted by the children's restlessness... All the apparatus is to be kept meticulously in order, beautiful and shining, in perfect condition... This means that the teacher also must be... tidy and clean, calm and dignified... The teacher's first duty is therefore to watch over the environment, and this takes precedence over all the rest. Its influence is indirect, but unless it be well done there will be no effective and permanent results of any kind, physical, intellectual or spiritual.

The teacher, now, must be most careful. Not to interfere means not to interfere in any way. This is the moment at which the teacher most often goes wrong. The child, who up to that moment has been very difficult, finally concentrates on a piece of work... Praise, help, or even a look, may be enough to interrupt him, or destroy the activity. It seems a strange thing to say, but this can happen even if the child merely becomes aware of being watched... The great principle that brings success to the teacher is this: as soon as concentration has begun, act as if the child does not exist... The duty of the teacher is only to present new things when she knows that a child has exhausted all the possibilities of those he was using before.
— Maria Montessori about the teacher
Scientific observation has established that education is not what the teacher gives; education is a natural process spontaneously carried out by the human individual, and is acquired not by listening to words but by experiences upon the environment. The task of the teacher becomes that of preparing a series of motives of cultural activity, spread over a specially prepared environment, and then refraining from obtrusive interference. Human teachers can only help the great work that is being done, as servants help the master. Doing so, they will be witnesses to the unfolding of the human soul and to the rising of a New Man who will not be a victim of events, but will have the clarity of vision to direct and shape the future of human society. - Maria Montessori, Education for a New World
— Maria Montessori, Education for a New World